Dynamical modeling of biogas production supported by an experimental anaerobic digestion process

This paper presents the development of a combined experimental and numerical approach to study the anaerobic digestion of both the wastes produced in a biorefinery using yeast for biodiesel production and the wastes generated in the preceding microbial biomass production. The experimental results show that it is possible to valorise through anaerobic digestion all the tested residues. In the implementation of the numerical model for anaerobic digestion, a procedure for the identification of its parameters needs to be developed. A hybrid search Genetic Algorithm was used, followed by a direct search method. In order to test the procedure for estimation of parameters, first noise-free data was considered and a critical analysis of the results obtain so far was undertaken. As a demonstration of its application, the procedure was applied to experimental data.

Strategic Orientations, Dynamic Capabilities, and Firm Performance: an Analysis for Knowledge Intensive Business Services

The strategic orientations of a firm are considered crucial for enhancing firm performance and their impact can be even greater when associated with dynamic capabilities, particularly in complex and dynamic environments. This study empirically analyzes the relationship between market, entrepreneurial and learning orientations, dynamic capabilities, and performance using an integrative approach hitherto little explored. Using a sample of 209 knowledge intensive business service firms, this paper applies structural equation modeling to explore both direct effects of strategic orientations and the mediating role of dynamic capabilities on performance. The study demonstrates that learning orientation and one of the dimensions of entrepreneurial orientation have a direct positive effect on performance. On the other hand, dynamic capabilities mediate the relationships between some of the strategic orientations and firm performance. Overall, when dynamic capabilities are combined with the appropriate strategic orientations, they enhance firm performance. This paper contributes to a better understanding of the knowledge economy, given the important role knowledge intensive business services play in such a dynamic and pivotal sector.

Escola, democracia e participação: o caso do agrupamento de escolas de Fronteira

O objetivo deste estudo é investigar sobre a participação e a democracia na escola, com base num estudo de caso. Trata-se de uma pesquisa qualitativa. Por meio de entrevista com o diretor e con-tatos com outros participantes na atividade da escola, procurou-se apreender como a democracia é entendida, quais as relações que os docentes estabelecem no interior da escola e como entendem o seu espaço de participação. Também procurámos, através da análise dos dados e da sua interpretação, reconhecer elementos significativos nos documentos que regem a vida da escola, nomeadamente o Regula-mento Interno. As reflexões finais desta pesquisa apontam para a necessidade de ampliação dos conceitos de democracia e participação e para a necessidade de formação docente voltada para as práticas participativas e democráticas e sua concretização no quotidiano escolar; ABSTRACT: The goal of this study is to investigate about participation and democracy at school, based on a study case. It is a qualitative re-search. Through interviews with the principal and contacts other par-ticipants in school action, we tried to realize how democracy is under-stood by them, which connections the teachers have inside school and how they see their space of participation. Also we tried, by the inter-pretative analysis of the data, recognize significant elements inside school documents, like Internal Rules. The final considerations of this research point to the necessity of an enlargement of the concepts of democracy and participation, and it is necessary that teachers reflect more deeply upon their participation and democratic practices and how these practices happen in school day by day.